You don't have wires, you have coil packs. Don't know about replacement schedule on those but it's not quite like a plugwire.
I would suggest looking around your cam covers for oil seepage; there is a small breather on the top of the cam cover that the gasket can go on, as well as the main cam cover gasket itself. If you don't have oil seepage it's not a problem. If so, the gaskets aren't much and aren't too terribly hard to change. Also, whatever is in your manual; probably the diff fluids and tranny fluid. I cannot remember if there is more though.